1. Field of the Invention
The present invention relates to an electromagnetic contactor having a magnetic core fastened inside a housing and acting in conjunction with a movable armature and having a coil wound onto a bobbin and surrounding a leg of the magnetic core. The invention relates especially to a contactor in which coil terminals that are arranged next to each other on one side of the bobbin can lie either on one side or the other side that is displaced by 180 degrees, and in which at least one male part comprising a terminal pin and at least one female part comprising a hole which receives the male part are disposed at the bordering areas of the bobbin and the housing.
2. Description of Related Art
An electromagnetic contactor of the type indicated above is known from U.S. Pat. No. 3,643,190. This contactor features a symmetrically constructed housing into which a magnetic core is fastened. A bobbin that is wound with a coil and ready for emplacement is provided for the middle leg of the magnetic core. The coil has coil terminals which are situated next to each other on one side of the bobbin. Four symmetrically arranged holes serving as female parts are provided in the housing that is provided for support of the bobbin. The bobbin is provided with four terminal pins servings as male parts that are arranged symmetrically with respect to the axis of the bobbin on its side that faces the housing that receives it. The terminal pins serving as male parts fit into the female parts of the housing. Since the housing as well as the support of the bobbin are constructed symmetrically, the bobbin can be assembled in two positions differing by 180 degrees during assembly.
The disadvantage of this arrangement is that the coil terminals may be arranged on both sides of the contactor, independent of the application. This leads to the possibility that, during the assembly of the contactor with an overload relay, the coil terminals may be situated on the side that is difficult to reach, namely, the side of the contactor that faces the overload relay. In this case, the contactor must be opened and the bobbin must be reassembled displaced by 180 degrees. Due to the labeling, the housing should be assembled only in a position that permits reading the labeling, and therefore it should not be possible to displace the housing at will by 180 degrees.
Swiss patent CH-A-244459 also describes a symmetrically constructed bobbin for electromagnetic devices that can also be placed on the magnetic core as desired in an initial position and a position displaced by 180 degrees, as long as the housing that is not specified in this document is also designed correspondingly. This arrangement also exhibits the previously indicated disadvantages.
German Offenlegungsschrift DE-Al 4406682 describes a contactor arrangement wherein the bobbin can only be placed on the magnetic core in one position. The coil terminals that are provided on one side of the bobbin must be on the side of the contactor that faces away and is displaced by 180 degrees. As a result, a different housing and a different bobbin must be produced for the other position, and these differing types must be kept in stock. This, however, results in considerable additional manufacturing and/or warehousing costs.